Rivet analyses

title: BELLE_2013_I1247463

Dalitz plot analysis of $\Upsilon(5S)\to\Upsilon(1,2,3S)\pi^0\pi^0$

Experiment: BELLE (KEKB)

Inspire ID: 1247463

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 88 (2013) 5, 052016

Beams: * *

Beam energies: ANY

Run details: - Any process producing Upsilon(5S), originally e+e-

Measurement of the mass distributions in the decays $\Upsilon(5S)\to\Upsilon(1,2,3S)\pi^0\pi^0$ by BELLE.

Source code:BELLE_2013_I1247463.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Upsilon(5S) -> Upsilon(nS) pi0 pi0 class BELLE_2013_I1247463 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2013_I1247463);


/// @name Analysis methods
/// @{

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 9000553);
  declare(ufs, "UFS");
  DecayedParticles UPS(ufs);
  UPS.addStable(PID::PI0);
  UPS.addStable(553);
  UPS.addStable(100553);
  UPS.addStable(200553);
  declare(UPS, "UPS");
  // histograms
  for (unsigned int ix = 0; ix < 3; ++ix)
    for (unsigned int iy = 0; iy < 3; ++iy) book(_h[ix][iy], 1 + ix, 1, 1 + iy);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  // find the Upsilon(5S) decays
  static const map<PdgId, unsigned int> mode[3] = {{{553, 1}, {111, 2}},
                                                   {{100553, 1}, {111, 2}},
                                                   {{200553, 1}, {111, 2}}};
  DecayedParticles UPS = apply<DecayedParticles>(event, "UPS");
  for (unsigned int ix = 0; ix < UPS.decaying().size(); ++ix) {
    unsigned int imode;
    for (imode = 0; imode < 3; ++imode) {
      if (UPS.modeMatches(ix, 3, mode[imode])) break;
    }
    if (imode > 2) continue;
    const Particles& pi0 = UPS.decayProducts()[ix].at(111);
    const Particle& ups = UPS.decayProducts()[ix].at(553 + imode * 100000)[0];
    double mUpsPi[2];
    for (unsigned int iy = 0; iy < 2; ++iy) mUpsPi[iy] = (ups.momentum() + pi0[iy].momentum()).mass();
    if (mUpsPi[0] < mUpsPi[1]) swap(mUpsPi[0], mUpsPi[1]);
    _h[imode][0]->fill(mUpsPi[0]);
    _h[imode][1]->fill((pi0[0].momentum() + pi0[1].momentum()).mass());
    _h[imode][2]->fill(mUpsPi[1]);
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 3; ++ix)
    for (unsigned int iy = 0; iy < 3; ++iy) normalize(_h[ix][iy], 1., false);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h[3][3];
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2013_I1247463);

} ```